Frey syndrome (auriculotemporal nerve syndrome) after parotidectomy involves gustatory sweating because parasympathetic secretomotor fibres aberrantly reinnervate sweat glands of the skin. What is the normal postganglionic course of these parasympathetic fibres to the parotid gland?

• A Submandibular ganglion → lingual nerve → parotid gland
• B Pterygopalatine ganglion → greater petrosal nerve → parotid gland
• C Otic ganglion → auriculotemporal nerve (CN V3) → parotid gland ✓
• D Ciliary ganglion → zygomaticotemporal nerve → parotid gland

Explanation

Parasympathetic secretomotor supply to the parotid: preganglionic fibres originate in the inferior salivatory nucleus (CN IX), travel via Jacobson's nerve (tympanic branch of CN IX) through the tympanic plexus and lesser petrosal nerve to synapse in the otic ganglion (in the infratemporal fossa, just below the foramen ovale). Postganglionic fibres 'hitchhike' on the auriculotemporal nerve (a branch of CN V3) to reach the parotid. After parotidectomy, these parasympathetic fibres regenerate aberrantly and reinnervate the sweat glands of the preauricular skin, so eating triggers sweating (Frey syndrome) instead of salivation.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.